The Little Blue Reasoning Book Part 11

Cause-and-effect fallacies exist when there is confusion about the causal relationship between two events. See if the argument is set up in terms of some situation aAa causing some situation aB.a Ask, aIs A really causing event B?a Show that A does not necessarily lead to B, and the argument is weakened or falls apart.

Here is a summary of how both arguments unfold: Opponentas argument: Conclusion: Students are better skilled.

a.s.sumption: There is a strong correlation between higher test scores and better skills. That is, parents are impressed because higher scores are an indication that students are better skilled.

Evidence: Parents are impressed.

Evidence: Test scores are getting higher.

Authoras argument: Conclusion: Students are better test-takers, not better skilled academically.

a.s.sumption: There exists no strong correlation between higher test scores and better skills.

Evidence: Studies confirm students are weaker in the basics.

Evidence: Test scores are getting higher.

Authoras note: SAT is a problem that serves to highlight the importance of identifying the evidence and conclusion, as well as the underlying a.s.sumption which links the evidence with the conclusion. In advancing another example, consider the person who says, aNo wonder Todd chose to attend a good university; he was setting himself up for the good job after graduation.a We cannot a.s.sume that Todd went to university for the purpose of getting a good job afterward. He may have gone to university to play on a varsity sports team, with the hope of playing professional sports. He may have gone purely for the academic experience, with no vocational thoughts at all, and then again, he may have gone just to get away from home, meet new friends, and enjoy himself socially.

Letas flow this example in terms of alternative causal explanations. Focus on each argumentas a.s.sumption.

Authoras original argument: Conclusion: The reason Todd chose to go to a good university was to get a good job upon graduation.

a.s.sumption: Going to a good university caused Todd to get a good job upon graduation.

Evidence: Todd went to a good university. He got a good job upon graduation.

To weaken this argument, we concentrate on finding an alternative explanation. There are at least three, as suggested below.

Argument #1: The sports person Conclusion: Todd went to a good university for the purpose of playing on a nationally recognized varsity sports team.

a.s.sumption: A person would not go to a good university and play on a well-known varsity sports team unless that was his or her primary motivation for doing so.

Evidence: Todd went to a good university. He played on a nationally recognized varsity sports team.

Argument #2: The academic Conclusion: Todd went to university for the academic challenge.

a.s.sumption: A person would not go to university and excel academically unless that was his or her primary objective for going to university.

Evidence: Todd went to a good university. He excelled academically.

Argument #3: The socialite Conclusion: Todd went to a good university to improve himself socially.

a.s.sumption: A person would not go to university and join several well-known clubs unless motivated to do so for social reasons.

Evidence: Todd went to a good university. He joined several well-known clubs on campus and met many new friends.

Back to problem Problem 21: Valdez Choice E. This choice would most weaken the original argument. Making a plausible alternative explanation serves to undermine the idea that Ms. Valdezas international marketing program was the reason for the jump in profits from 8 to 15 percent. The alternative explanation suggests that the increase in profits is due to a corporate acquisition prior to Ms. Valdezas appointment as president which doubled Zipcoas annual revenues. We do have to a.s.sume in choice E that revenues and profits are linked proportionately; nonetheless it is still the best choice.

None of choices A through D brings us close enough to increased revenues or profits. They all mention potentially positive things, but we donat have a clear a.s.surance that they brought in the bucks (dollars). Choice B, perhaps the best wrong answer choice, simply says that production capacity has increased. We do not know whether an increase in production capacity equals an actual increase in production, or if such an increase in production has resulted in more profits.

Back to problem Problem 22: Headline Choice C. The idea that low self-esteem may be the cause of both obesity and depression most weakens this argument. Here, obesity and depression are deemed the joint effects of another single cause a" low self-esteem.

Per choice A, it is not essential to the argument that one understands why he or she is depressed or how to escape from depressionas grip. It is only essential that obesity be the cause of depression. In choice B, it is not necessary for obesity to be the only cause of depression; there could be many ways to become depressed besides becoming obese. In choice D, it is not necessary that obesity and depression be linked proportionally, even if causally related. Depression could occur whenever one is declared aoverweight,a even though it would be logical to a.s.sume that one who is more overweight is also to some degree more depressed. Per choice E, the terms adesperationa and asuicide,a even if linked to depression, are outside the scope of the claim a" aobesity is linked to depression.a Back to problem Problem 23: TV Viewing Choice E. One way to destroy or seriously damage a causal relationship (e.g., A causes B) is to show that it is not A that causes B but B that causes A. This is what choice E does by suggesting reverse causation. It suggests that aggressive people go looking for violent TV programming, not that violent TV programming makes people aggressive.

Choice A may weaken things a bit, but not drastically. The fact that some viewers in the high-viewing group experienced lower aggression levels than did other subjects in the high-viewing group is not an improbable result. What matters is that more high-viewers experienced more aggression overall relative to low-viewers. Ditto for choice B. Choice C is incorrect because it is irrelevant whether fear did or did not cause some viewers to restrict their viewing. If it did, it will only mean that these viewers should have shown fewer signs of aggression because they werenat viewing as much. The reason that they are not viewing is effectively irrelevant. Choice D is also irrelevant; what matters is that people actually viewed the programs, not whether the programs were live or pre-recorded.

Back to problem Problem 24: Shark Choice B. First, letas go to the incorrect answer choices. Answer A is the closest to the correct answer because it generally supports the idea that surfers in other areas are also not being attacked. Choice A slightly strengthens the original argument. Choice C weakens the argument, suggesting that there are no sharks left in the reserve. Choice D also weakens the argument by suggesting that an alternative explanation (e.g., wristbands with metal bells) may be key to understanding why sharks are not attacking surfers. Choice E is essentially irrelevant; we are talking about surfers, not divers or tuna. In choice B (correct answer), what we really want to know is whether sharks attack surfers wearing black suits while avoiding surfers wearing metallic suits.

What do you need in order to prove that metallic suits really work? The framework for setting this problem up is the basis for experimental design problems, as seen in real-life research.

This problem highlights the trap of proof by selected instances. People trying to prove the efficacy of wearing metallic suits cite examples from categories (a) and (d). That is, they cite instances of surfers wearing black suits and getting attacked by sharks (see aaa) and also cite instances of surfers in metallic wet suits who do not get attacked by sharks (see ada). People trying to prove the efficacy of wearing traditional black suits cite examples from categories (b) and (c). That is, they cite instances of surfers wearing metallic suits and getting attacked by sharks (see aca) while citing instances of surfers wearing black suits and not getting attacked by sharks (see aba).

It is quite possible that in recent months there havenat been any shark attacks. In such an event, any comparison about the efficacy of wearing metallic suits would prove fruitless, as depicted in the chart below containing hypothetical numbers.

If we had actual numbers for all boxes, we could make a percentage comparison to determine whether wearing a metallic suit really made a difference. The number of surfers wearing black suits who were attacked by sharks would be divided by the total number of surfers wearing black suits. The number of surfers wearing metallic suits who were attacked by sharks would be divided by the total number of surfers wearing metallic suits. A comparison of these two percentage figures would yield a conclusion.

Authoras note: Below is an original statement enclosed in quotation marks. Which of the two statements that follow add most support for the original statement?

Original: aFirm ABC is spending money on advertising and seeing an increase in sales. Clearly advertising is causing the increase in sales.a Statement I: Other competing firms are also spending money on advertising and seeing an increase in their sales.

Statement II: Without spending money on advertising, Firm ABC would not have seen an increase in sales.

The answer is statement II. Although statement I lends some support to the proposition that advertising expenditure is leading to an increase in the sales of Firm ABC, what we really want to know is the opposite a" what happens when we do not spend money on advertising. If we do not spend money on advertising, we would expect to see a resulting decrease in current sales levels. If not, then this would call into question whether advertising is really causing our sales to increase and suggest that another cause is responsible for the increase in sales.

Back to problem Implementation a.s.sumptions Problem 25: Solar Energy Choice C. If research has not yet developed an effective way to capture and store solar energy in a way that most families can employ, then this would seriously weaken the argument. This aplana will not work if we lack the prerequisite technological capability to implement the solution.

Choice A is irrelevant. Choice B slightly weakens the argument by suggesting that powerful utility monopolies are acting in their own self-interest by not presenting fair and impartial information. Choices D and E bring the issue of cost into play but the argument made suggests other considerations besides costs that favor the adoption of solar energy. For example, solar energy is superior because it eliminates air and water pollution, and in the case of nuclear energy, the threat of radiation.

Back to problem Problem 26: Cla.s.sics Choice E. In order for a plan to work, desire or motivation on the part of the individual or organization must be present. Here, the operative word is acana and the ability to do something does not necessarily translate to the awilla to do something. aCana does not equal awilla!

Perhaps the easiest way to summarize the problem is to say that just because most literate people have not read the cla.s.sics does not mean that they are necessarily lazy. Most literate people may simply choose not to spend their time doing so. Also, even if a person is lazy, he or she may still be able to read the cla.s.sics. For example, the literate but lazy person may just read very slowly or in fits and starts but still arrive at the finish line. All we do know is that some people have likely read the cla.s.sics. For all we know, some of these people might be motivated and some might be lazy. We cannot a.s.sume that all of the people who have read the cla.s.sics belong to the motivated group.

Choice D is not correct because the original statement is not a true aif a thena statement, meaning that the contrapositive is not a valid inference, as it would otherwise be (see Exhibit 5.3). The original statement only states that a person who is literate and not lazy acana read the cla.s.sics.

Here is an example which ill.u.s.trates how choice D might have been a correct choice. Say the original statement was a true aif a thena statement as follows: Hypothetical: aIf a person is literate and is not lazy then he or she will read the cla.s.sics.a Here, the contrapositive leads to a correct inference.

Statement: aIf a person has not read the cla.s.sics then he or she is a literate person who is lazy!a Authoras note: Here is a follow-up problem highlighting a common a.s.sumption as found in an everyday setting. A plan may not be feasible due to lack of financial wherewithal.

Economic recessions are opportunities for industrial change. Industries are forced to close their doors and throw workers out of jobs. In due course, some of the workers thus displaced from work become the entrepreneurs who drive new industries; others learn new skills so that when the economy revives they can join in a new pattern of industry.

The speaker in the pa.s.sage above a.s.sumes which of the following?

A) The innovative ideas of entrepreneurs seem so radical that they are ignored until such time as no other solutions present themselves.

B) Economic recessions require a society to reevaluate its economic priorities and its methods of production.

C) Some of the workers displaced by an economic recession have, or are able to find, the financial resources to support themselves while learning new skills.

D) The overall effect of an economic recession is to eliminate inefficient industrial methods and thereby make room for new industrial methods.

E) An economic recession affects all members of a society regardless of their economic positions.

The correct answer is choice C. The original argument sounds persuasive enough: economic recessions provide new opportunities for persons out of work to learn new skills and again become productive. However, the pa.s.sage a.s.sumes that a person has the wherewithal (financial resources) not only to support him- or herself while out of a job but also to pay to acquire new skills. Choices A and E are essentially irrelevant. Choices B and D are trickier. However, these two choices essentially restate the claim made in the original argument and do little to damage the a.s.sumption.

Try approaching this problem using cla.s.sic argument structure. The conclusion is the very first sentence a" aEconomic recessions are opportunities for industrial change.a The rest of the sentences are evidence, i.e., aIndustries that are forced to close throw workers out of jobs. In due course, some of the workers thus displaced from work become the entrepreneurs who find new industries; others learn new skills so that when the economy revives they can join in a new pattern of industry.a After you re-read the conclusion, stop and ask yourself: why are economic recessions opportunities for industrial change? The reason is contained in the evidence (or premises). Basically, they are opportunities because people can retrain themselves. Once you have answered this question, it becomes much more obvious that this argument a.s.sumes that people have the time and money to retrain themselves.

Back to problem Problem 27: Public Transportation Choice A. The fact that there may be better or easier ways to lower pollution levels in most major cities falls outside the scope of this argument. The argument only concerns itself with the idea that people should leave their cars at home and take public transportation to combat pollution. Also outside the scope of this argument would be the idea that most major cities have other more pressing problems, such as poverty, crime, or affordable housing.

This question was chosen to highlight implementation a.s.sumptions that can occur in critical reasoning problems. Choices B, C, D, and E are all valid implementation a.s.sumptions. Choice B questions whether enough people actually own cars or use them to drive to work. In the most basic sense, if people do not own cars the argument is irrelevant. Choice C highlights a lack of required opportunity to make a plan work. Public transportation must be both available and accessible should someone decide to switch. Choices D and E highlight unantic.i.p.ated bottlenecks, namely, whether the current public transportation system can accommodate all the people who decide to switch, as well as meet financial requirements.

Back to problem Problem 28: Rainbow Corp Choice B. If Tina is not aware of the recent newspaper articles featuring Rainbow Corp. as an environmental culprit, it does not make sense to conclude that she does not care about the environment. Choices A and C are irrelevant. In choice D, even if the companyas public relations department didnat issue a statement denying that it violated the law, this does not mean that the company is guilty of any wrongdoing. Rainbow Corp.as actual guilt or innocence has no impact on the issue at hand because Tina has no idea of the indictment. In choice D, the fact that Tina was a member of an environmental protection organization during her freshman and soph.o.m.ore years in college weakens the claim a little, but not substantially.

Authoras note: Letas review another example. Suppose that a certain global think tank is reviewing national anthems and the significance of their historical themes. It concludes that most national anthems have militaristic themes due in part to their creation during times of war or other conflict. Therefore, the think tank recommends that in the context of preserving global peace and stability, countries should consider changing their national anthems to rid them of any militaristic references. What would weaken this claim? Any suggestion that citizens today are unaware of the presence of any militaristic themes in their countriesa national anthems.

Back to problem Problem 29: Personality Choice C. A fundamental a.s.sumption is that business school interviewers can accurately identify the traits which lead to success in business school. If, for example, affability (friendliness) is a desired trait, then how will an interviewer judge whether a candidate possesses this quality? If intelligence is a desired trait, does this translate to looking for polished speaking ability, a perceived a.n.a.lytical mindset, or the ability to tell interesting stories? In general, how will an interviewer ascertain whether the candidate has a winning personality?

Choice A is a distortion. The interview may be an integral part of the interview process but not result, in and by itself, in a successful admissions effort. Good interviewing may be correlated with a successful admissions effort but not be the cause of a good admissions effort (i.e., correlation vs. causation). Also review Necessary vs. Sufficient Conditions, covered in chapter 5. Good interviewing is likely a necessary but not a sufficient condition for a generally good admissions process.

Choice D is also a distortion. The interview need not have only one purpose. In addition to a.s.sessing candidatesa personalities, interviewers might wish to seek clarification with respect to the applicantsa backgrounds. Business schools might even use the interview as a public relations tool, helping to promote their schools so that in the event a candidate is accepted, the candidate would be more likely to accept the schoolas offer. In choice B, we donat know for sure whether the interview is the most important element in the admissions process.

With reference to choice E, there is no need for interviews to be held at similar times and places in order for them to be effective. Different interview venues do not necessarily imply inconsistency with respect to interview procedures or outcomes.

Back to problem Problem 30: Yuppie Caf Proposed Solution in Outline Form The argument concludes that you can use the Internet to advertise and make your business more profitable. The author uses as evidence the fact that Yuppie Caf advertised on the Internet and its business increased by 15% over last yearas total. I do not find this argument to be well reasoned, as it rests on several debatable a.s.sumptions.

Attacking the a.s.sumptions a First, the argument a.s.sumes that a 15% increase in business is the same as a 15% increase in revenue or profit. The term abusiness increasea must be clarified in order to enable a proper comparison.

a Second, the argument a.s.sumes a cause-and-effect relationship between advertising on the Internet and the increase in business.

a Third, the argument a.s.sumes that Yuppie Caf is representative of all other businesses a" e.g., your own business.

a Fourth, the argument a.s.sumes that companies have access to the Internet in order to place company advertis.e.m.e.nts, and that they employ personnel capable of administering the system. The argument also a.s.sumes that a company has the money to spend on Internet advertising. These considerations create implementation a.s.sumptions. Finally, the argument likely a.s.sumes that the costs of Internet advertising do not outweigh the revenues to be received.

Attacking the evidence a Within any given industry, achieving a business increase is easier for a younger business than for an older, more mature business. A typical businessas natural growth cycle is characterized by an upward growth curve which flattens as the business matures. A younger business is more likely to have significant year-to-year growth. An increase in business will result in a higher percentage increase given that the increase is compared to a relatively smaller base.

Conclusion a In conclusion, to strengthen this argument, we need more information to substantiate the cause-and-effect, representative sample, comparison and a.n.a.logy a.s.sumptions, and implementation a.s.sumptions mentioned above.

a We could also strengthen the argument by softening the absolute wording as used in the original argument. The original sentence states, aTheir success shows you how you too can use the Internet to make your business more profitable.a The wording could instead read, aTheir success shows how you too can probably use the Internet to make your business more profitable,a or aTheir success shows how a number of companies can use the Internet to make their businesses more profitable.a a Finally, we need clarification as to what exactly the word asuccessa means. How is it defined?

Proposed Solution in Essay Form The argument concludes that you can use the Internet to advertise and to make your business more profitable. The author uses as evidence the fact that Yuppie Caf advertised on the Internet and its business increased by 15% over last yearas total. I do not find this argument to be well reasoned, as it rests on several debatable a.s.sumptions.

First, the argument a.s.sumes that there is a cause-and-effect relationship between advertising on the Internet and an increase in business. It could be that Yuppie Caf saw an increase in business for reasons not related to advertising on the Internet. For example, a major compet.i.tor of Yuppie Caf may have gone out of business, the company may have started serving a higher-quality coffee product, business may have increased because word-of-mouth advertising lured customers, or perhaps there was a period of general economic prosperity.

Second, the argument a.s.sumes that Yuppie Caf is representative of all other businesses, e.g., your own business. This creates a representative sample a.s.sumption. It may even be true that the Internet does help highly customer-oriented companies with their businesses, e.g., coffee shops, health spas, and book distribution companies. But what about an oil-and-gas or mining company? Obviously, it is difficult to generalize from a single example to all other companies.

Third, the argument a.s.sumes that other companies actually own computers, have access to the Internet in order to place company advertis.e.m.e.nts, and employ personnel capable of administering the system. Furthermore, the argument a.s.sumes that a company has the money or other financial wherewithal to spend on Internet advertising. Moreover, the argument a.s.sumes that the money a company spends on Internet advertising does not outweigh the revenues to be derived from increased sales. These considerations create implementation a.s.sumptions.

Fourth, the argument a.s.sumes that a 15% increase in business is the same as a 15% increase in profit. The word abusiness increasea likely refers to revenues, but, as we know, revenues and profit are not the same thing. Profit depends on the relationship between costs, revenues, and sales volume. Furthermore, the words abusiness increasea are vague. For example, a 15% increase in the number of customers served may not translate to a 15% increase in revenues or profits, particularly if the retail price of a cup of coffee has been significantly reduced or increased.

In conclusion, to strengthen this argument we need more information to substantiate the cause-and-effect relationship between advertising and an increase in business. We need more examples in order to show that Yuppie Caf is not merely an exceptional business example. We need some a.s.surance that companies have access to the Internet in the first place. We also need clarification as to whether an increase in business translates to an increase in revenues and/or whether an increase in revenues translates to an increase in profit.

One word a" asuccessa a" is particularly vague and needs clarification. Is a 15% increase in business a worthy criterion for asuccessa? To a venture capitalist, success might be defined by a return of 50% or more. Furthermore, should success be measured merely along a quant.i.tative dimension? What about the qualitative dimensions of employee or consumer satisfaction? Finally, softening the wording in the original argument could strengthen the argument. The original sentence states, aTheir success shows you how you too can use the Internet to make your business more profitable.a The wording could read, aTheir success shows how you too can probably use the Internet to make your business more profitable,a or aTheir success shows how a number of companies can use the Internet to make their businesses more profitable.a Back to problem

CHAPTER 5 a" MASTERING LOGIC.

Problem 31: Chemist Choice B. This problem highlights the fallacy of affirming the consequent. The circle representing chemists appears inside the bigger circle representing scientists, so all chemists are definitely scientists. But the reverse is not true. Not all scientists are chemists; other than chemists, there are many types of scientists, including biologists and physicists.

In choices A and D, the first part of each statement is correct while the latter half is incorrect. Choices C and E are both totally incorrect.

Back to problem Problem 32: Intricate Plots Choice C. The last line of the introductory blurb gives us an aif a thena statement which serves as the pa.s.sageas conclusion aIf scriptwriting is to remain a significant art form, its pract.i.tioners must continue to craft intricate plots.a In determining what the author would most probably agree with, we need to look for logically deducible statements. Choice C, the correct answer, forms the contrapositive. aIf a script does not have an intricate plot, it will probably not be a significant art form.a Choice A is an example of the fallacy of affirming the consequent, and tip #41 highlights this erroneous deduction. It is likely that other factors besides intricate plots also go into the making of a significant art form. Choice B is the fallacy of denying the antecedent. Choice D is outside the scope of the argument; we do not know whether scriptwriting is the most likely art form to become a significant one. Choice E is out; there is no reason to believe that more is better; perhaps one intricate plot per script is enough.

Back to problem Problem 33: Campus Pub Choice D. This example highlights the fallacy of denying the antecedent. Looking back at the original, we find that just because it is not final exam week does not necessarily mean that the campus pub is not selling a lot of beer. For all we know the campus pub sells a lot of beer every week because it is a popular pub. It is certainly likely that the campus pub does sell a lot of beer during final exam week, when students seek to relieve stress or celebrate. There could also be other lucrative weeks, particularly when sports matches such as football and basketball are being played.

In choice D, just because no one is happy doesnat necessarily mean some people wonat smile. There could always be those people who smile regardless of whether they are happy or sad. Look at the original statement and concentrate on finding a similar structure.

Original Argument (fallacious): final exam week a' sell lots beer (if itas final exam week then the pub sells a lot of beer) a final exam week a' a sell lots beer (if itas not final exam week then the pub does not sell lots of beer) Now match this structure with correct choice D: If happy a' smile a happy a' a smile Back to problem Problem 34: Balcony Choice C. We are told that all apartments above the fifth floor have balconies. We cannot, however, logically infer that apartments on or below the fifth floor do not have balconies. Answer choices B and E provide tempting traps. For all we know, every apartment from the first floor on up has a balcony.

Authoras note: The statement, aIf a person is rich, then he or she will vote in favor of a tax cut,a does not mean that if a person is poor he or she will not also vote in favor of a tax cut.

Tip #44 states that one way to think about an aIf a thena statement in the form of aIf A, then Ba is that just because A leads to B does not mean that C, D, or E could not also lead to B. Case in point: The fact that increased expenditures on advertising have led to an increase in company sales does not mean that an increase in company sales could not have been achieved through other means a" hiring more salespersons, lowering the retail price of products, or hiring a famous, talented manager.

Back to problem Problem 35: Global Warming Choice D. If we want to stop global warming then we must pa.s.s legislation. As foreshadowed by tip #45, we must draw an important distinction between necessary and sufficient conditions. Pa.s.sing legislation is necessary to stopping global warming, but it is not a sufficient condition for doing so. It is not a sufficient condition because several other factors probably are necessary to stopping global warming. For starters, in all cases we may need more than just legislation; we may need legal enforcement of approved laws. Moreover, other factors may need to be present as well, such as the need to legislate to preserve forested areas. Furthermore, choice C is a near-identical restatement of the original statement. Answer choices A and B are all correct interpretations of Jacquesa original aIf a thena statement. However, since Pierre believes Jacquesa statement is not true, we must look for an erroneous answer choice.

Choice E is an opposite answer choice. Pierreas mistake consists in believing that legislation is the sole causal agent in stopping global warming (as opposed to one of several factors); his misunderstanding does not lie in the belief that legislation is an ineffective step toward stopping global warming.

Hereas a related but simpler example: Jacques: If you want to keep your pet dog alive, you must give it water every day.

Pierre: Thatas not true. It takes a lot more than water to keep your pet dog alive.

Pierreas response is inaccurate because he mistakenly believes that what Jacques has said is that A)*Giving water is necessary to keeping your pet dog alive.

B)*Only the giving of water will keep your pet dog alive.

C)*If your pet dog is to be kept alive, it must be given water.

D)*Giving water is enough to keep your pet dog alive.

E)*Your pet dog will not be kept alive by giving it water.

Choice D above is, of course, the correct answer. Jacquesas statement correctly identifies water as a necessary condition for keeping your pet dog alive. Pierre has mistakenly a.s.sumed that Jacques has said that water is a sufficient condition for keeping your pet dog alive.

Back to problem Problem 36: Sales Choice B. Letas repeat what Debra said: To be a good salesperson, one must be friendly.